if [ -z ${var+x} ]; then echo "var is unset"; else echo "var is set to '$var'"; fi 参考:https://stackoverflow.com/questions/3601515/how-to-check-if-a-variable-is-set-in-bash 6、换算秒为分钟、小时 代码语言:javascript 代码运
其中,VARIABLE_NAME是你定义的环境变量的名称。 如果你想在Bash脚本中设置环境变量,可以使用以下语法: 如果你想在Bash脚本中设置环境变量,可以使用以下语法: 这将在当前的Shell会话中设置环境变量,并在后续的脚本步骤中可用。 如果你想在Jenkins项目的配置中设置环境变量,可以在"环境变量"部分添加一个"键/值"对。然...
/bin/bashecho${var:-"Variable is not set"} ---> Variable is not setecho"1 - Value of var is ${var}" ---> 1- Value of var isecho${var:="Variable is not set"} --->Variable is not set 同时var已经被赋值为Variable is not setecho"2 - Value of var is ${var}" --->2 -...
# "VARIABLE =value"# ^#% Script tries to run "VARIABLE" command with one argument, "=value".# "VARIABLE= value"# ^#% Script tries to run "value" command with#+ the environmental variable "VARIABLE" set to "".#---## 变量引用echohello# hello# Not a variable reference, just the s...
pipe_in=-1, pipe_out=-1, fds_to_close=0x81519e8) at execute_cmd.c:2243 #6 0x08072e1e in execute_command_internal (command=0x8151088, asynchronous=0, pipe_in=-1, pipe_out=-1, fds_to_close=0x81519e8) at execute_cmd.c:885 ...
In this example we declare simple bash variable and print it on the screen ( stdout ) with echo command. #!/bin/bash STRING="HELLO WORLD!!!" echo $STRING 1. 2. 3. Your backup script and variables: #!/bin/bash OF=myhome_directory_$(date +%Y%m%d).tar.gz ...
Here's an example one-line command to do that: PROFILE=/dev/null bash -c 'curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.3/install.sh | bash'Installing in DockerWhen invoking bash as a non-interactive shell, like in a Docker container, none of the regular profile ...
This is an alternative to sed, awk, perl and other tools. The function below works by finding all leading and trailing white-space and removing it from the start and end of the string. The : built-in is used in place of a temporary variable....
While ShellCheck is mostly intended for interactive use, it can easily be added to builds or test suites. It makes canonical use of exit codes, so you can just add ashellcheckcommand as part of the process. For example, in a Makefile: ...
PROMPT_DIRTRIM variable) \W the basename of the current working directory, with $HOME abbreviated with a tilde \! the history number of this command \# the command number of this command \$ if the effective UID is 0, a #, otherwise a $ ...